A conventional automatic telephone answering apparatus is shown in FIG. 1. When a call signal (ring signal) from a caller's telephone set 11 arrives via exchange 12, it is detected by a bell signal detection circuit 13 connected to exchange 12 through normally closed contact 140 of a first relay 14 as described below. Bell signal detection circuit 13 includes a timer which is started in response to detection of a calling signal to render first relay 14 of the self-hold type operative. This results in closure of normally open contact 141 of first relay 14 and establishment of a speaking path wherein telephone circuit A-A' is connected to one side of line transformer 15.
At the same time, normally open contacts 142 and 143 of first relay 14 are closed and motor 16 is activated to the drive state through normally closed contact 201 of second relay 20 which is activated by closure of normally open contact 143 of first relay 14. Endless tape 17 is thus driven by motor 16 and plays back through playback head 18 a prerecorded reply message via playback amplifier 19 and a normally closed contact 203 of the second relay 20. This is transmitted by line transformer 15 to the caller's telephone set 11.
When the endless tape 17 has circled once, conductive foil 17a on tape 17 short-circuits a pair of electrodes 21 and the second relay 20 is made operative by normally open contact 143 of the first relay 14, which was previously in the open state. The second relay 20 becomes self-holding through closure of its normally open contact 205.
At the same time, normally open contact 202 of the second relay 20 is opened, thereby stopping motor 16 and activating motor 22 into the drive state. Translation of recording tape 23 is thus started by motor 22, permitting a message from the caller to be recorded on tape 23 via normally open contact 204 of second relay 20 which is now closed, recording amplifier 24, and recording head 25.
When the timer action of the bell signal detection circuit 13 terminates after completion of a previously specified tone, first relay 14 is again rendered inoperative, resulting in second relay 20 again being made inoperative due to the opening of normally open contact 143 of first relay 14. The relay actions of the first and second relays 14 and 20 are thus terminated, and the speaking path returns to its original stand-by state.
In the above system, the caller starts speaking in response to the reply message given by endless tape 17 and a beep tone that follows this message. Conventional automatic telephone answering apparatuses such as described above have the disadvantage that, since a beep tone emitted following the reply message is used to notify a caller that he can start leaving a message, it is difficult to judge the time when one can start talking. Also the beep tone is discordant and gives an unpleasant sensation. The fact that correct timing of the start of talking is difficult results in a wasteful running of the recording tape 23. It is therefore often impossible to completely record the desired message before the recording time runs out. Another problem is that it is difficult to take effective measures to notify the caller of the end of recording tape 23.
In cases in which a called subscriber uses an external telephone circuit to carry out a remote-control action for read-out of telephone messages that have been received while he is away, there is the inconvenience that there is no way of knowing how many telephone calls have been made or how many messages have been recorded until all of the recorded portion of the recording tape has been completely heard. Also, further loss of time results because it is only possible to know that the last message has been reached by letting the tape overrun for a bit.
Further problems with prior art apparatuses are that it is required to record information regarding time and other items before or after the message is recorded, it is necessary to have a complex arrangement using external equipment, and it is not possible to take effective measures to give the caller time information before or after the message is recorded.
Another problem with prior art apparatuses is that there is a tendency for the telephone to remain needlessly engaged, since there are no effective measures for detecting when the caller has replaced the receiver.
In cases in which the subscriber is not out but quite near the telephone, he might sometimes wish to simply hear a message from a caller without directly answering the telephone, but lack of provision for this does not give the subscriber that choice.
A further problem has been that the endless tape that carries a prerecorded reply message is played over and over again and therefore has a comparatively short life.
Another problem is that there are no effective measures in relation to the arrival of a number of calls during the same period, including the time when speaking is proceeding.
Yet another problem is that use of an endless tape and a recording tape frustrates attempts to reduce power consumption or to reduce the overall size and weight of the equipment.
A further problem is that maintenance of secrecy in remote-controlled read-out necessitates use of special complex equipment.